A container known from EP2354037 as pressurized container 2 for the application of polyurethane foam is for example shown in FIG. 1. This type of container 2 may contain for example a viscous foaming product or a liquid under pressure. According to the known example depicted in FIG. 1, the container 2 comprises a dome 4 in which a valve 3 is installed through which, when the valve 3 is opened, a flow of expanding foam will be released from the container 2. This type of container 2 is generally available for use in a variety of applications such as for example sprayable construction foams and insulation foams, more specifically polyurethane foams, and are for example used in industrial or do-it-yourself applications. As will be described in more detail, it is known that the valve 3 comprises a valve stem 10 that is installed via an opening in the dome, such that a passage will be opened, for example when the container makes a tilting motion through which the liquid can be released via the valve stem 10 from the pressurized container. In order to operate the valve 3, an adapter 30, as depicted in FIG. 2, is mounted to the valve 3 by means of an mounting device 1. As is generally known by a man skilled in the art, the foam is transported via the adapter 30 to for example an attached dispensing tube 6 in order to apply the foam at the desired location.
An embodiment of a mounting assembly is known from EP2004520 where an adapter, or an adapter connecting piece, is mounted to a valve stem by pressing in axial direction until hooks at the bottom of the adapter clipped onto the conical widening of the valve stem. This type of mounting assembly gives rise to the problem that when pressure is applied to mount the adapter onto the valve stem, there is the risk of the valve being moved to the open position, as a result of which foam is allowed to flow out before the adapter is clipped, which then results in undesirable leaking.
To counter this problem an alternative mounting assembly 1 known from EP2354037 is available, as depicted in FIGS. 1 and 2. This mounting assembly 1 for mounting an adapter 30 to a valve stem 10 of a valve 3 of a pressurized container 2 for applying a foaming product comprises, as depicted, the valve stem 10 and the adapter 30. The valve stem 10 is largely tubular and extends axially, that is, according to the indicated direction A formed by the central axis of the largely tubular structure of the valve stem, between a selectively closable intake opening 11 at an end 13 of the valve stem 10 that is located inside the container 2 and a discharge opening 14 formed by the opposing axially extreme downstream end 14 of the valve stem 10. With a tilting movement of the valve stem 10, for example by means of an adapter 30 mounted to it, the intake opening 11 is cleared and a stream of foam can flow out of the container 2 through the internal passage 15 of the largely tubular valve stem 10, and channeled through the internal passage 35 respectively of the adapter 30 and the internal channel 5 and the attached dispensing tube 6 further downstream to the location of the application of the foam. It is clear that the foam flows through an internal passage from the intake opening to a discharge opening of respectively the adapter 30 and subsequently the dispensing tube 6.
This valve stem 10 comprises, as depicted in the sectional view of FIG. 2, a tubular male mounting portion 12 positioned at the outside of container 2. This means that the mostly tubular valve stem 10 can be divided into two main elements according to the axial direction A of the internal passage 15, that is, a tubular male mounting portion 12 for the mounting of the adapter 30 that thus is available for that purpose at the side of the valve 3 positioned at the outside of the container 2, and an internal valve element 17 that extends through the valve 3 into the inside of the container 2. It is clear, as is depicted in FIG. 2, that the internal valve element 17 of the valve stem 10 is sealed in a known way from the outside of the container 2 with a suitable sealing element 19 with which for example it cooperates to enable the valve operation of the valve 3, as described in more detail in EP2354037.
This male mounting portion 12 of the valve stem 10, as depicted in FIGS. 1 and 2, extends tubularly according to the axial direction A at the outside of the valve 3 of the container 2 up to the extreme downstream end 14 that comprises the discharge opening of the valve stem 10. The male mounting portion 12 is tubular, meaning that its exterior wall 16 and its inner wall that creates the internal passage 15 have a central axis along the axial direction A. The male mounting portion 12 comprises a radially extending collar 18 at its exterior wall 16, that according to the embodiment shown has a conical design. It is clear that this collar 18 is axially positioned between the extreme downstream end 14 and the opposite extreme upstream end 13 of the valve stem 10, and further that it is positioned at the exterior side of the valve 3 and the container 2, and that it is positioned axially at the mounting portion 12 compared to the extreme downstream end 14 at a position closer to the intern valve element 17. Between this extreme downstream end 14 and the collar 18, the male mounting portion 12 comprises a male threaded element 20 in the form of for example a suitable screwthread 20 that is applied to the exterior wall 16 of the male mounting portion 12 at least a part of the axial zone between the extreme downstream end 14 and the radially extending collar 18 extending from exterior wall 16.
The adapter 30 from EP2354037 comprises an internal passage that extends from an extreme upstream end 34 up to the extreme downstream end 33. The adapter 30 comprises a female mounting portion 32 that is suited for the male mounting portion 12. The female mounting portion 32 also extends tubularly from the extreme downstream end 34 of the adapter 30. At the inner wall 36, the female mounting portion 32 comprises a female threaded element 40 that, as depicted in FIG. 2, is suited to screw onto the male threaded element 20 of the valve stem 10, by means of an axial screwing movement in the direction indicated with the arrow R. In this way, the adapter 30 is mounted to the valve stem 10, by means of the axial screwing movement of both corresponding screw elements 20, 40 until the mounted position 50 is reached as depicted in FIG. 2. As known from the embodiments in for example EP2354037, and as depicted in FIG. 2, the collar 18 is positioned such that it limits the axial screwing movement up to mounted position 50. According to the embodiment shown, this means that at the end of the screwing movement, when reaching the mounted position 50, the adapter 30 with a radial widening 38 at its inner wall 36 near the extreme upstream end 34 sits against the collar 18 of the male mounting portion 12. The mounting by means of the axial screwing movement avoids the risk that an axial force on the valve 3 in the direction R is exerted during the mounting of the adapter 30 which would be large enough to move the valve 3 away from its closed position and would for example clear one or more inlet openings 11. However, this kind of mounting assembly 1 may give rise to another problem, especially in a context such as for example known from EP2743002 where the downstream end of the dispensing tube 6 may be closed off. In such a case, there is a risk that, for example as the result of increased pressure in the closed dispensing tube 6 and adapter 30, the adapter may 30 inadvertently unscrew itself from the mounted position 50 as a result of which the closure of the screwed connection is no sealed and could allow inadvertent leaks.
There thus exists a need for an improved mounting assembly that solves the problems described above and that reduces the risk of the mounting assembly coming loose while in the mounted position, without increasing the risk of leakage when mounting the adapter.